Friday, March 29, 2024

Why Green Hydrogen Should Be Part of the Energy Mix in Zambia

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By Dr Roy Moobola

Zambia’s Energy Mix

Zambia is not endowed with large proven reserves of fossil-fuel resources such as coal, oil or natural gas. Currently all petroleum products in Zambia are imported which leaves the country at risk to global energy shocks. The vast majority of the electricity supply (83%) is dependent on hydro sources which have become prone to effects of climate change in the form of uncertain rainfall patterns and increasingly frequent droughts. Recent electricity supply deficits in 2015 and 2020 have had a detrimental effect on economic growth and poverty reduction. This is a picture of a country with too narrow a range of energy sources and too dependent on imported fuel.

The bulk of primary energy used in Zambia is obtained from biofuels with 73% coming from this source in 2019. This consists mainly of solid biomass such as firewood and charcoal. The large reliance on biomass is not sustainable and has negative consequences for local environments in the form of increased deforestation and pollution. Oil and other imported petroleum products make up 12% of the energy supply. There is increased local production of bioethanol for blending with petrol at a ratio of 1:10 which would slightly reduce the dependence on oil. Hydro-electric power contributes only 10% of the energy supply despite its economic importance. The variation of primary energy supply sources in Zambia between 1990 and 2019 is shown in the figure below.

Figure 1: Total primary energy supply by source, Zambia 1990 – 2019 [1]
Figure 1: Total primary energy supply by source, Zambia 1990 – 2019 [1]
To increase energy resilience and security of supply the Zambian energy sector needs to diversify where and how it sources its energy. The recent shocks to world fuel prices caused by the Russia-Ukraine military action have brought into sharp focus the need for energy self-reliance in many countries. To reduce energy supply risks and the amount of foreign exchange spent on importing fuel, more of the energy used in Zambia needs to be obtained from sustainable local sources.
Increasing use of renewable energy sources for electricity and the development of battery technology for transportation are transforming the energy landscape. This change presents itself as an opportunity for countries such as Zambia which have abundant water, sunshine and wind resources but an underdeveloped energy sector.

Hydrogen

Hydrogen has been touted as the fuel of the future in the energy transition from fossil fuels to low carbon energy. Many technological innovations are being made to ensure that hydrogen is a safe and cost-effective product to generate, store, transport and use. According to projections, the global final energy mix will rapidly shift towards electricity and hydrogen, with one estimate that the two technologies will represent 32% of the global energy mix by 2035 and 50% by 2050. This trend is shown in the figure below.

Figure 2: Projections for the global final energy consumption mix until 2050 [2]
Figure 2: Projections for the global final energy consumption mix until 2050 [2]

Hydrogen is a high energy density carrier with 3 times the energy density of petrol. It can be used as a feedstock in industries that are dependent on expensive imported petroleum fuels. Hydrogen can act as energy storage for excess or intermittent electricity generation from renewable energy solutions. Strategies to attain universal energy access in Zambia could use hydrogen as leapfrog technology in areas with low energy access. For example, bottled hydrogen may be used to provide low carbon cooking solutions in difficult to electrify rural areas. As a locally produced fuel, hydrogen would have the potential to transform the energy sector in the country.

Green hydrogen is created using renewable electricity in an electrolyser by splitting water into its constituent parts. Green hydrogen can be used to link renewable electricity generation with sectors that are difficult to electrify such as heat for industry and as a fuel for large vehicles.

Because of its physical location and suitable natural resources Zambia is predicted to be able to produce green hydrogen that would be competitive in price on the world market as shown in the figure below. According to this assessment southern and western parts of the country should be able to produce hydrogen at a price less than $2.2/kg at some point between 2030 and 2050. This estimated future hydrogen price is compared with current energy prices in the table below.

 

Figure 3: Hydrogen costs from hybrid solar PV and onshore wind systems in the long term [3]
Figure 3: Hydrogen costs from hybrid solar PV and onshore wind systems in the long term [3]

Table 1: Comparison of projected hydrogen price with current energy prices for similar fuels in Zambia

 

 

Fuel price

Calorific value

Density

Price of energy

 

$/kg or $/litrea

MJ/kgb

kg/litre

$/MJ

Hydrogen

2.2

120

 8.9 x 10-5

0.24

Dieselc

1.48

43

0.85

0.53

LPGd

2.5

46

0.54

0.69

 

  1. $/kg for hydrogen and LPG, $/litre for diesel
  2. https://www.engineeringtoolbox.com/fuels-higher-calorific-values-d_169.html
  3. Diesel price of K25.65/litre and exchange rate of $17.3/K
  4. Liquefied petroleum gas, estimate based on K810 for 19 kg, May 2021 price

 

Electrolysers

The technology necessary to successfully deploy clean energy is largely imported into Zambia. A new technology and innovation ecosystem needs to be developed in which industry, academia and government work together to select and develop the most appropriate technology needed to solve local problems and generate wealth in the country. One technology that could be of benefit to Zambia is the development and manufacture of electrolysers.

Electrolysers use electricity to convert water into hydrogen and oxygen. Electrolysers come in three main types: alkaline, polymer electron membrane (PEM) and solid oxide. Alkaline electrolysers are the most used type in industrial settings. They use electrodes made of iron, nickel and nickel alloy sometimes with cobalt catalysts which would make this technology relatively accessible for sourcing materials in Zambia. By contrast PEM electrolysers require more exotic rare materials like iridium and ruthenium. Both alkaline and PEM electrolysers operate at relatively low temperatures (< 80°C). Solid oxide electrolysers are still in development in part due to technical problems caused by their operation at temperatures greater than 700°C.

Figure 4: Schematic and properties of alkaline electrolyser [4]
Figure 4: Schematic and properties of alkaline electrolyser [4]
Figure 4b chematic and properties of alkaline electrolyser [4]
Figure 4b chematic and properties of alkaline electrolyser [4]

Energy Storage

Hydrogen can be used to store energy when there is an excess of renewable electricity supply and for transportation to difficult to electrify locations. Many rural areas have low population densities in which the economics do not support extending the national electric grid to these locations. Stored hydrogen fuel offers an alternative to battery storage technology and liquefied petroleum gas (used extensively in some countries such as India and Brazil) to provide energy to remote areas or for cooking purposes. Compressed ammonia gas is an effective means of storing and transporting hydrogen and could be deployed for both small and large-scale energy storage needs. It is noted that for short term storage needs such as diurnal cycles, batteries would provide a more efficient means of energy storage whereas hydrogen would be more suited to longer duration storage. The figures below demonstrate this.

Figure 5: Energy capacity vs storage duration for hydrogen and other storage technologies [4]
Figure 5: Energy capacity vs storage duration for hydrogen and other storage technologies [4]
Figure 6: Relative efficiency of electricity generated from battery and hydrogen stored energy [4]
Figure 6: Relative efficiency of electricity generated from battery and hydrogen stored energy [4]
Fertiliser Manufacture

Green hydrogen can be used as a feedstock for industrial processes. Hydrogen when combined with nitrogen from the air forms ammonia which is a precursor to nitrogen-based fertiliser (urea and ammonium nitrate) manufacture. Current methods of ammonia and fertiliser production are energy intensive and use natural gas (methane) as a feedstock. The natural gas is reformed at high temperatures using steam to obtain hydrogen and carbon dioxide. The figure below shows how the process to create fertilisers from green hydrogen might work.

Figure 7: Green ammonia and low carbon fertiliser production [5]
Figure 7: Green ammonia and low carbon fertiliser production [5]
Zambia imports fertiliser at great cost though there are attempts to increase local fossil fuel-based fertiliser manufacture. Between 1972 and 2015 Sable Chemicals in Zimbabwe used electrolysers powered by hydro-electric energy to produce green hydrogen and ammonia for fertiliser manufacture. Ammonia production was stopped in 2015 due to a persistent country-wide energy deficit and increased electricity tariffs. Zimbabwe now imports ammonia gas from South Africa.

Steel Manufacture

Green hydrogen can also be used as a source of heat for industrial processes. In the Zambian context the most notable industrial use would be steel manufacture.
Replacing coal with hydrogen is a promising option still in development for decarbonising the steel production process. The main Zambian steel manufacturing facility, UMCIL Kafue Steel, uses a coal-based direct reduction process for the conversion of iron oxide ore to direct reduced iron. Green hydrogen can be used to replace coal as a reducing agent.

Hydrogen Cooking Solutions

Clean energy solutions are required to reduce the dependence on biofuels such as charcoal and firewood. Indiscriminate use of such fuels causes deforestation, damages ecosystems and exacerbates climate change. Additionally, many people exposed to the pollution of these fuels experience poor health outcomes. Green hydrogen offers an alternative cooking fuel in places that are difficult to reach with conventional grid or off-grid solutions. Combining bottled hydrogen with hydrogen gas cookers could be the way to solve the energy deficit in remote areas.

Figure 8: Hydrogen cooking solutions [6]
Figure 8: Hydrogen cooking solutions [6]

Transportation Vehicles

Whilst electric batteries have taken a lead in decarbonising the passenger vehicle sector, alternative clean energy solutions are needed for heavy goods and larger passenger vehicles. Currently electric vehicle battery technology does not provide the power or range requirements for larger vehicles. Hydrogen offers a potential solution with the development of fuel cell or synthetic fuel technology.

Fuel cells work like batteries but combine hydrogen and oxygen to create electricity, which is opposite to what an electrolyser does. Recently, Anglo American unveiled the world’s largest hydrogen-powered truck weighing 220 tonnes at a platinum mine in South Africa in an aim for the mining company to be carbon neutral by 2040, as shown in the figure below.

Figure 9: South Africa Launches world’s biggest hydrogen-fuelled truck [7]
Figure 9: South Africa Launches world’s biggest hydrogen-fuelled truck [7]
Alternatively, synthetic fuels can be made from the combination of green hydrogen and carbon dioxide to form a man-made liquid fuel similar to petrol, diesel or kerosene.

Namibia

In late 2021 the Namibian government announced plans to invest $9.4 billion over 40 years in green hydrogen production in collaboration with German consortium Hyphen Hydrogen Energy. The factors in favour of this investment are the abundant solar and wind energy resources in Namibia, proximity to the sea and significant reserves of platinum and iridium required to manufacture polymer electrolyte membrane electrolysers. The level of proposed investment is all the more remarkable considering that Namibia’s GDP in 2020 was $10.7 billion. The initial project phase worth $4.4 billion would create a 2 GW renewable energy electricity plant due to open in 2026. Further expansion at the end of the decade would generate a total of 5 GW of renewable energy capacity and 3 GW of electrolyser capacity.

Conclusion

A diversity of energy sources reduces risks to security of supply and increases the resilience of a country’s energy sector. Since Zambia imports all of its petroleum products, transitioning to an energy type that can be generated locally is important to establishing energy security, for wealth creation and improving balance of payments.

Manufacture of hydrogen electrolysers would provide an opportunity to create value-added industries using locally available minerals such as nickel and cobalt. Further development of much needed local industry, such as the manufacture of fertilisers and steel, can be enhanced using cheaper locally sourced fuels.

It is vital that appropriate research and development is undertaken to own technologies that are likely to form part of the future energy mix. Close collaboration is required between industry, academia and government to achieve the necessary technological upgrading and the transition to innovation-based economic growth.

The array of potential energy technologies that could be developed in Zambia include solar PV, concentrated solar thermal power, wind turbines, electric vehicle batteries, electrolysers, fuel cells, green hydrogen and synthetic fuels. A systems analysis approach would be necessary to determine which are the most optimum technologies to develop further within the Zambian economy.

The direction of the future global energy mix, abundance of renewable energy sources and water in Zambia, and the strategic and economic benefits of having a locally sourced fuel provide a strong case for the development of hydrogen technology solutions.

References

  1. https://www.iea.org/countries/zambia
  2. Global Energy Perspective 2022, McKinsey and Company, https://www.mckinsey.com/industries/oil-and-gas/our-insights/global-energy-perspective-2022
  3. The Future of Hydrogen, International Energy Agency, June 2019, https://www.iea.org/reports/the-future-of-hydrogen
  4. Carbonomics, The clean hydrogen revolution, Goldman Sachs, Feb 4 2022, https://www.goldmansachs.com/insights/pages/carbonomics-the-clean-hydrogen-revolution.html
  5. Green Ammonia and Low-Carbon Fertilizer Production in 2050, Fertlizers Europe, https://www.fertilizerseurope.com/paving-the-way-to-green-ammonia-and-low-carbon-fertilizers/
  6. Solar Hydrogen for Cooking in the Global South, École Polytechnique Fédérale de Lausanne (EPFL), https://www.epfl.ch/labs/lrese/sunhydrogencooking/
  7. South Africa launches the world’s biggest hydrogen-fueled truck, https://www.citizen.co.za/news/3092243/south-africa-launches-the-worlds-biggest-hydrogen-fueled-truck/

Dr Roy Moobola is a specialist in energy solutions and a university lecturer in engineering.

10 COMMENTS

  1. Thank you for this informative article. Just wondering what the capacity of our local research and technological innovation is to develop PEM electrolysers that can produce cost competitive green hydrogen. Along with that would be the need for innovative systems for storage and distribution that are viable in our local context. It would be good for the Ministry of Green Economy to be more active in letting us know what strategic efforts and developments are being worked on.

  2. Dr Moobola elucidates a compelling argument for why Zambia should include hydrogen technology in its future energy mix. If Zambia were to tap into this source of energy along side Hydro and Solar, that would be a giant step to achieving its energy security. To realise this, nonetheless, GRZ must sort out the energy tariff fiasco that has made ZESCO a non viable business. Opening up the energy sector would attract private sector investment and make possible suggestions that Dr Moobola has so eloquently outlined in his article.

  3. Dr. Moobola, thank you very much for such an insightful article on the use of hydrogen for clean energy solutions. The country is at a critical juncture in terms of meeting the energy requirements of a growing population, an economy needing an energy boost as well as diversification of energy sources. You have laid out the case for hydrogen, and in clear terms. This is great!

  4. Thanks for this well researched article.
    It is time we reviewed our generation mix to include renewables and emerging technologies. There is still a lot of R&D required to make Hydrogen viable for a country like Zambia but we need to start planning beyond Hydro and Fossil Fuels. It is time to engage the Ministry of Energy and Ministry of Green Economy with some of these solutions.

  5. I hope you’ve copied this article to the Ministries of Green Economy and Education. My advice to Roy is that as an educationist he should split the article into smaller educational material for consideration by the curriculum development centre. Most of this can be learnt at O’Level. It just requires a change in the curriculum. Further, I propose that you produce a paper with estimates for a pilot project. NCZ is better suited for such a project, especially that the still plant is just across the road. This is a viable project that only requires a roadmap and estimates to attract financiers. DBZ comes to mind. My observation is that several projects can come out of this presentation. It’s only that CEC are used to the monotony of buying power from Zesco and selling it to the mines…

  6. Japan is going this way. We could learn a lot from them if we engage them and they are more than willing to invest in this form of renewable energy as well as to give us the technology and know how.

  7. Let’s hope Mutati reads this…………

    Thank you , very informative.

    It all about investing in green energy……

    the new Dawn GRZ needs to growth the economy for funds and throw everything at green energy to reduce reliance on fossile fuels…………

  8. Hydrogen is indeed the fuel of the future in the energy transition. Thanks to Dr. Moobola for this well researched topic. Hope the Green Economy Ministry can incorporate these brains in order to add value to the energy sector in Zambia.

  9. I think this story hasn’t received the prominence it deserves. What has put China where it is today is technology. It has simplified skills training. You’d be surprised that most of these Chinese at construction sites are bricklayers, carpenters and electricians. Despite their wealth of knowledge our engineers are being supervised by less qualified persons. So it’ll be unfortunate if this article ends here, just like many other papers. There are many projects that can come out of this. They can in turn create many jobs for our idle youths. To me skills training should start as early as grade 6 so that those that drop out at grade 7 will go with some skill. You don’t need to spend 3yrs in a college to be a carpenter, bricklayer, artisan fitter, auto electrician & mechanic, plumber, etc…

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